Many current storage systems utilize an industry standard serial channel protocol known as Fibre Channel Arbitrated Loop. In accordance with this protocol, disk drives communicate with a server via a high speed serial link. The disk drives and server are interconnected in a ring or loop topology. Each disk drive on the loop has an individual address assigned to it, known as an Arbitrated Loop Physical Address (ALPA). Each Fibre Channel Arbitrated Loop can include up to 126 ALPAs.
Storage systems are commonly designed in a modular fashion, wherein a number of disk drives are installed within a standard rack mount enclosure such as a 3U enclosure. The enclosures are in turn installed in a rack mount chassis and interconnected to form the storage system. Individual disk ALPAs are assigned based upon the disk's position within the enclosure, and based upon the identity of the enclosure within the system. In some current systems, enclosure identity is determined through manual switch settings. This is disadvantageous because the switches consume valuable space on the enclosure and because human error can cause addressing problems. In other current systems, intelligence is provided in the rack mount chassis itself to set the enclosure addresses, disadvantageously adding cost and complexity to the chassis. It would be desirable to provide a disk drive addressing scheme that avoids these inadequacies and shortcomings.